Protective shield for fastener driving tools



Oct. 30, 1962 B. J. ELLIOTT ETAL v 3,

PROTECTIVE SHIELD FOR FASTENER DRIVING TOOLS Filed Aug. 19, 1959 nwmmes: BER/VAR!) c/sssz ELL/0T7- 159N557 fiosem pETHEKEf/D GE MS iv A TTOKIV United rates fdaten 3,066,433 PRQTECTWE SHlELD Milt FASTENER DRTWNG TUGLS Bernard Jesse Elliott, Clifton Hill, Victoria, and Ernest Robert Petherbridge, Hampton, Victoria, Australia, assignors to Ulin Mathieson {Ihemical Corporation, New

York, N.Y., a corporation of Virginia Filed Aug. 19, 1959, Ser. No. 834,704 6 tliaims. (Cl. 14t.5)

This invention relates to an improved protective shield for tools used for driving studs or other fasteners into concrete and structures generally, and is particularly suited for explosive powered tools to protect the operator from flying chips, fragments, dust and other matter resulting fro-m the explosion of the propelling charge or the penetration of the stud or fastener into the structure.

Protective shields at present provided on such tools are fixed usually in one position or another and thus prevent the use of the tool in positions both away from and close up to side walls or other obstructions. The present invention has for its object to overcome such difficulty.

According to the invention, there is provided a shield comprising a section fixed relative to the muzzle end of the tool, a section slotted to receive this end of the tool and movable in relation to said fixed section and the muzzle end of the tool so as to be displaceable by pressure contact against a side wall or other obstruction where the tool is used close up to the latter, a cam operated slot closure and spring means acting on the movable section to return it to normal position after displacement.

The invention is more fully described aided by reference to the accompanying drawings wherein:

FIG. 1 is a top view of one form of the improved shield and showing its position on a work surface when the tool is being used close up to a side wall or obstruction.

FIG. 2 is a sectional view on line Z-2 of FIG. 1 and showing the shield on the work surface.

FIG. 3 is a view of the inner side of the shield.

FIG. 4 is a View similar to FIG. 3, but showing an alternative form of shield according to the invention.

FIG. 5 is a side view of FIG. 4.

Referring initially to FIGS. 1 to 3, 1 indicates the fixed or base section of the tool shield and 2 the laterally movable section, each relative to the tool barrel. The section 1 is secured to a tubular casing 3 on the muzzle end 4 of the tool barrel and carries pins 5 which extend into channels 6 on guide members 7 secured to the peripherally adjustable or edge section 2. Said channels house coiled compression springs 8 which at one end bear against the pins 5 and at the other end against plugs 9 fitted into the ends of the channels. When, however, the tool is used, it is section 2 which is placed against a sidewall 15 of the work while section 1, hereinafter called the base member 1, is the section which moves relative to section 2. and the side wall. The springs 8 function to maintain the edge section 2 of the shield in the normal position shown in FIG. 3, where no peripheral edge part of section 2 extends less to one side than to the opposite side.

The edge section 2 has a slot 1% to provide clearance for the muzzle end 4 of the tool where said base section is moved against the influence of the springs 8.

Base section 1 is unsymmetrically fixed with respect to the casing 3 on the tool muzzle end 4%, as shown in FIG. 1, in such a way that the muzzle 4 can be placed most closely to the periphery of edge section 2 as in FIG. 1. Base section 1 is fixed with respect to the tool muzzle end 4, while edge section 2 is adapted for being considered fixed with respect to some side wall structure such as 15 of the workpiece. With base section 1 considered fixed, section 2 is movable relative to section 1. Regardless .of

Fate-muted 0st. 30, 1962 the viewpoint taken, sections 1 and 2 are laterally displaceable relative to each other.

In the normal position of the base section 1 and edge section 2, the slot 1th is covered by a flap 11 which is pivoted at 12 to the inner side of the section 2 and is movably supported by a bracket 13. The flap has a cam slot 14 which received the muzzle end 4 of the tool, or the casing 3 thereon. in the normal position of the shield shown in FIG. 3, the muzzle end 4 of the tool is substantially at the centre of the composite shield and the flap 11 covers the slot ltl. The shield, in the absence of any side Wall 15, is thus usable in the normal manner.

When the tool is being used close up to a side wall or other obstruction, the shield is pressed against the side wall or obstruction in such manner as will slidably displace the movable section 1 to one side of section 2 within the limit of slots 1d and 14- to the extent required. FIG. 1 shows the action. The edge section 2 is held by the pressure contact with the side wall 15, and in relation to section 2, section 1 and the muzzle end 4 of the tool are movable against the coiled springs 3 which are compressed in the channels 6 between the pins 5 and the end plugs 9. Thus, the too-l can be used close up to the side wall 15 with the shield and its marginal flange 16 still maintain ing the required protection against flying chips, fragments or other matter; away from any side Wall the sections 1 and 2 are ready to assume the full shield relationship automatically under the bias of the spring.

As the slidable section 1 and section 2 are displaced, the cam slot 14 causes the flap to move on its pivot 12 and progressively uncover the slot 16 When the tool is removed from contact with the side wall 15, the coiled springs 8 automatically return the displaced movable section 2 to normal position with respect to base section 1 and tool end 4 and, at the same time, the cam slot 14 causes the flap 11 to be pivotally moved so that it again covers the slot 11 in movable section so that flying chips or fragments cannot escape through said slot when the tool is used in its normal manner. Maximum peripheral adjustability is obtained by linear displacement in the lateral direction by the arrangement of this invention with the tool end 4 unsymmetrically on section 1 and with slot ill unsymmetrically in section 2, while flap 11 and its carn slot provide the necessary movement and safe coverage with the shield at all times.

In the alternative embodiment shown in FIGS. 4 and 5, the movable base section 101 is constructed to slide over the edge section 1 02. The usual marginal flange 216 of the shield is formed, in the case of the inner section tee, with grooves 17 which slide on interior ribs 18 in the flange 116 of outer section 101. The movable section 162 i returned to normal position by a leaf spring 19 anchored at one end 20 to the flange of the base section w ll and having its outer free end 21 bearing against the edge of the movable section 102. The flap 111 is, in this construction, of disc shape having as in the other embodiment spiral slot 114 but functions in the same manner as the previous construction. Slot is a deep notch in the edge of 192 for cooperation with barrel 4 and easing 3 with respect to slot 114.

With the improved shield, the difficulty previously mentioned is overcome and the general utlility of the tool is increased.

What we claim is:

1. A protective shield for explosive actuated stud driving tools of the type having an elongated barrel and a stud projecting normally shield-centered muzzle end of said barrel, said shield comprising a transverse base section mountable on the tool adjacent said muzzle end, an extendable edge section over-lapping said base section and movable in a direction laterally in relation to said base section and muzzle end so as to adapt said base section to be displaceable on one side relative thereto to dispose said end of the barrel nearer a side wall or like obstruction by manual pressure contact upon lateral abutment of said edge section with said side wall when the tool is used close up to the latter, resilient means continually acting on both side sections to return and continually bias them to a normal barrel centered position after displacement, a main slot in the edge section sufficiently elongated in said direction to receive and provide clearance for said muzzle end and the relative movement of said end and sections to an extremity beyond full overlapping coverage of said slot by said base section, and cam track and follower means receiving said end and extending outwardly therefrom for mounting on said edge section and muzzle end for oscillation to automatically maintain said main slot covered at said extremity under both said relative movement and also the action of said resilient means.

2. A protective shield for explosive actuated stud driving tools of the :type having an elongated barrel and a stud projecting normally shield-centered muzzle end of said barrel, said shield comprising a transverse base section mountable on the tool unsymmetrically offset on one side adjacent said muzzle end, an extendable edge section movable laterally in relation to said base section and ofiset muzzle and so as to adapt said base section to be displaceable on said one side relative thereto to dispose said end of the barrel nearer a side wall or like obstruction by manual pressure contact upon lateral abutment of said edge section with said side wall when the tool is used close up to the latter, resilient means continually acting on both side sections to return and continually bias them to a normal barrel centered position relative to each other after displacement, a main slot elongated and unsym metrically oifset on said side in the edge section to receive and provide clearance for said muzzle end and the relative movement of said end and sections, and means having an auxiliary slot receiving and functioning with said muzzle end to automatically maintain said main slot covered under both said relative movement and also the action of said resilient means when said sections are simultaneously returned to said normal position, under the bias of said resilient means.

3. A protective shield as claimed in claim 2 wherein the edge section has parallel spaced protective channels and the base section has pins which extend into said channels on the movable section, said channels housing coiled compression springs which, at one end, act on the edge section adjacent its extendable edge and which, at the other end, act on the base section, the coiled springs forming the resilient means for returning the base section to normal position after displacement.

4. A shield as claimed in claim 2 wherein at least the base section has two opposing parallel marginal flanges and the edge section is constructed to slide within said base section between said flanges and wherein a leaf spring is anchored at one end to the base section and at its free end bears against an edge of the edge section, said leaf spring forming the resilient means for returning the base section to normal position and biasing it there after displacement.

5. A shield as claimed in claim 4 wherein the edge section has opposing marginal flanges with grooves mating with and sliding on ribs on the marginal flanges of the base section.

6. A protective shield for explosive actuated stud driving tools of the type having an elongated barrel and a stud projecting normally shield-centered muzzle end of said barrel, said shield comprising a transverse base section mountable on the tool adjacent said muzzle end, an extendable edge section overlapping said base section and movable in a direction laterally in relation to said base section and muzzle and so as to adapt said base section to be displaceable on one side relative thereto to dispose said end of the barrel nearer a side Wall or like obstruction by manual pressure contact upon lateral abutment of said edge section with said side wall when the tool is used close up to the latter, resilient means continually acting on both said sections to return and continually bias them to a normal barrel centered position after displacement, a main slot in the edge section sufficiently elongated in said direction to receive and provide clearance for said muzzle end and the relative movement of said end and section to an extremity beyond full overlapping coverage of said main slot by said base section, and cam track and follower means receiving said end and extending outwardly therefrom for mounting on said edge section and muzzle end for oscillation to automatically maintain said main slot covered at said extremity under both said relative movement and also the bias of said resilient means, said cam track and follower means comprising a flap formed of a plate pivoted on said edge section and having a curved cam slot receiving said muzzle end whereby said flap is simultaneously moved to maximum flap coverage of the cam slot when the sections are returned to said normal position.

References Qited in the file of this patent UNITED STATES PATENTS 2,785,401 Henning Mar. 19, 1957 2,785,402 Henning Mar. 19, 1957 2,787,000 Smith et al. Apr. 2, 1957 2,952,020 Schulz Sept. 13, 1960 FOREIGN PATENTS 809,012 Great Britain Feb. 18, 1959 

